A laser electrode assembly comprised of an X-Y array of cathode pin electrodes and a planar anode electrode for use in a high pressure gas laser is disclosed in detail in U.S. Patent Application Ser. No. 674,264 entitled "DC Excitation Of High Pressure Gas Lasers", filed Apr. 6, 1976 as a continuation of Application Ser. No. 365,387, filed May 30, 1973, and assigned to the assignee of the present invention. This application, which is incorporated herein by reference, discloses the advantages of the pin electrode array in a flowing laser gas system and discusses the technique for ballasting the individual pins through the use of discrete resistors associated with the rows and columns of the pin electrodes comprising the X-Y array. The application further indicates the potential use of an electrolyte solution contacting the pins as a basis for providing a resistive ballast between the discrete pins and a voltage supply. The resistive ballast in combination with transverse laser gas flow in the above-referenced application functions to stabilize the glow discharge.
The ballast resistors employed in the multiple pin cathode electrode assemblies must: (1) dissipate up to 30% of the input energy to the discharge; (2) be compact in order to permit a large number of pin electrodes to be assembled with densitites of up to several pins per square centimeter; (3) withstand momentary high currents and voltage in the event of arc instability; and (4) exhibit sufficient insulation to prevent electrical flashover to nearby resistors as well as surrounding parts of the laser system.